Exploiting the potential of autophagy in cisplatin therapy: A new strategy to overcome resistance

Resistance to cisplatin is a major challenge in the current cancer therapy. In order to explore new therapeutic strategies to cisplatin resistance, we evaluated, in a model of lung cancer (H1299 and H460 cell lines), the nature of the pathways leading to cell death. We observed that H1299 displayed a natural resistance to cisplatin due to an inability to trigger an apoptotic response that correlates with the induction of autophagy. However, pharmacological and genetic approaches showed how autophagy was a mechanism associated to cell death rather than to resistance. Indeed, pro-autophagic stimuli such as mTOR or Akt inhibition mediate cell death in both cell lines to a similar extent. We next evaluated the response to a novel platinum compound, monoplatin, able to promote cell death in an exclusive autophagy-dependent manner. In this case, no differences were observed between both cell lines. Furthermore, in response to monoplatin, two molecular hallmarks of cisplatin response (p53 and MAPKs) were not implicated, indicating the ability of this pro-autophagic compound to overcome cisplatin resistance. In summary, our data highlight how induction of autophagy could be used in cisplatin resistant tumours and an alternative treatment for p53 mutated patient in a synthetic lethally approach.This work was supported by grants from Fundación Leticia Castillejo Castillo and Ministerio de Economía y Competitividad (grant SAF2012-30862 to RSP and grant CTQ2011-24434 to FAJ). RSP Research Institute, and the work carried out in his laboratory receive support from the European Community through the regional development funding program (FEDER). JGC received funding from the Regional Ministry of Education and Science of Castilla–La Mancha (FPI-JCCM) and from Fundación Leticia Castillejo Castillo. MCC and RSP have a contract from the INCRECYT progra